CN112032326A

CN112032326A - Segmented piston valve core structure, assembly, valve and method thereof

Info

Publication number: CN112032326A
Application number: CN202010850033.0A
Authority: CN
Inventors: 钱锦远; 母娟; 高志新; 金志江
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2020-08-21
Filing date: 2020-08-21
Publication date: 2020-12-04
Anticipated expiration: 2040-08-21
Also published as: CN112032326B

Abstract

The invention discloses a segmented piston valve core structure, a component, a valve and a method thereof. The valve core structure comprises a valve core main body, a movable block and an annular sealing element; the bottom surface of the valve core main body is a plane with a through hole in the center; the movable block is horizontally arranged in the through hole, and the bottom surface of the movable block is a plane; the periphery of the movable block is hermetically connected with the side wall of the through hole through an annular sealing element to form a watertight sealing surface of the valve core; the annular sealing element has telescopic elasticity, so that the movable block can turn over when receiving unbalanced moment. The piston type valve core is divided into the valve core main body directly contacted with the sealing device and the movable block subjected to unbalanced moment by the blocks, under the action of the unbalanced moment, the movable block overturns, and the valve core main body contacted with the sealing device keeps the original vertical direction, so that the phenomenon that the sealing device is extruded due to the unbalanced moment is avoided. The invention has simple structure and easy manufacture, and can be widely popularized and applied.

Description

Segmented piston valve core structure, assembly, valve and method thereof

Technical Field

The invention relates to a piston type valve core structure, in particular to a segmented piston type valve core structure, a component, a valve and a method thereof.

Background

In the valve adopting the piston type valve core structure which is horizontally arranged, the stress on the bottom surface of the valve core shows obvious unbalanced phenomenon, the pressure on the lower surface of the bottom surface of the valve core close to the fluid outlet side is larger than the pressure on the lower surface of the bottom surface of the valve core close to the fluid inlet side, the unbalanced pressure distribution phenomenon enables the bottom surface of the valve core to generate unbalanced moment, and the unbalanced moment is mainly concentrated in the middle position of the bottom surface of the valve core. The piston type valve core has a tendency of lateral overturning due to the existence of unbalanced moment, and finally the wall surface of the valve core extrudes a sealing byproduct, so that the driving energy consumption is increased, the sealing performance is influenced, and the leakage failure of the valve can be influenced even under the working condition of large flow.

In the piston valve structure on the market at present, there is no improved design for compressing the sealing device by the unbalanced moment applied to the valve core, and particularly, there is no valve core structure for partitioning the surface directly contacting the sealing device and the surface applied with the unbalanced moment. Chinese utility model patent CN208997362U discloses a piston flow control valve, and the axis of this structure valve shaft is gapped with the axis of valve body, makes the radial force that the case received reduce, and switching torque, also reduce the wearing and tearing to the fitting surface. But the valve structure still has abrasion between the valve core matching surfaces, and the structure is more complex and has no universality.

Disclosure of Invention

The invention aims to solve the problem that the existing piston type valve core is unbalanced in stress and provides a sectional type piston valve core structure.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

in a first aspect, the present invention provides a segmented piston valve cartridge comprising a valve cartridge body, a movable block, and an annular seal; the bottom surface of the valve core main body is a plane with a through hole in the center; the movable block is horizontally arranged in the through hole, and the bottom surface of the movable block is a plane; the peripheral side of the movable block is in sealed connection with the side wall of the through hole through the annular sealing piece to form a watertight sealing surface of the valve core; the annular sealing element has telescopic elasticity, so that the movable block can turn over when receiving unbalanced moment.

Preferably, the through hole is circular, the movable block is circular plate-shaped, the diameter of the through hole is larger than that of the movable block, and the through hole and the movable block are concentrically arranged.

Furthermore, the annular sealing element is an annular corrugated pipe, the annular corrugated pipe is formed by coaxially nesting and sealing connecting a plurality of annular corrugated sections with diameters increasing from inside to outside, the innermost annular corrugated section is connected with the movable block, and the outermost annular corrugated section is connected with the valve core main body; the annular corrugated pipe has a telescopic freedom degree in a radial direction and a bending freedom degree in a non-radial direction.

Further, the annular corrugated pipe is a metal corrugated pipe.

Furthermore, the metal corrugated pipe, the movable block and the through hole are welded and fixed.

Preferably, the valve core main body is a hollow cylinder, the bottom surface is a circular ring plane, and the peripheral surface is a cylindrical surface.

In a second aspect, the invention provides a piston valve core assembly, which comprises a sleeve, a sealing filler, a valve seat, a spring and the segmented piston valve core in any one of the first aspect; the spring is used for applying pre-pressure to the segmented piston valve core to enable the sealing surface of the segmented piston valve core to be pressed on the valve seat to form a sealing pair for controlling the opening and closing of the flow path; the sleeve is assembled outside a valve core main body of the segmented piston valve core, and the sleeve and the valve core main body form a moving pair for controlling the valve core main body to slide along the axial direction; the valve core main body and the sleeve are kept sealed through sealing filler.

Preferably, one end of the spring is supported on the top surface of the movable block, and the other end of the spring is supported on the external valve cover and keeps a compressed state.

In a third aspect, the invention provides a piston type valve, which comprises a valve body and a valve cover assembled on the valve body, and is characterized in that the piston type valve core assembly in any one of the second aspects is installed in the valve body.

In a fourth aspect, the present invention provides a method for overcoming unbalanced moment in a piston valve as described in the third aspect, wherein the piston valve core is divided into a valve core main body directly contacting with the sleeve and the sealing packing and a movable block for bearing the unbalanced moment by a partition, after the valve is opened, the unbalanced moment is concentrated at the position of the movable block in the middle of the sealing surface, under the action of the unbalanced moment, the movable block is overturned to counteract the unbalanced moment, and the valve core main body contacting with the sleeve and the sealing packing maintains the original vertical orientation, thereby avoiding the sleeve and the sealing packing from being extruded due to the unbalanced moment.

Compared with the prior art, the technical scheme of the invention has the following advantages:

(1) the invention relates to a block type piston valve core structure, which divides the contact surface of a piston valve core and a sealing device and the surface which receives unbalanced moment into a valve core main body and a movable block, wherein the unbalanced moment mainly occurs in the middle part after a valve is opened, the movable block is overturned under the action of the unbalanced moment, and the valve core main body which is in contact with a sleeve and sealing filler keeps the original vertical direction, thereby avoiding the phenomenon of extruding the sealing device caused by the unbalanced moment.

(2) According to the sectional type piston type valve core structure, the valve core main body and the central block are connected by the metal corrugated pipe, the metal corrugated pipe is a spring-like structure which can stretch under the action of external force, no gap exists between two adjacent circles, the diameter of each circle is increased from inside to outside, the relative opposition of the positions and the movement modes of the two valve cores is ensured, and the sealing performance of the piston type valve core is also ensured.

(3) The valve core structure is simple in structure and convenient to manufacture, and is suitable for most valves with circular valve core structures.

Drawings

FIG. 1 is a cross-sectional view of a segmented piston-type cartridge construction according to the present invention closed;

FIG. 2 is a bottom view of a segmented piston type valve core structure according to the present invention;

fig. 3 is a schematic diagram of a general piston type valve core and a block type piston type valve core structure according to the present invention when opened, (a) is a schematic diagram of fluid distribution and a valve core overturning tendency under an unbalanced moment when the general piston type valve core is opened; (b) the invention relates to a schematic diagram of turning over of fluid distribution and movable blocks under the action of unbalanced moment when a segmented piston type valve core structure is opened;

FIG. 4 is a schematic view of the flow and flow lines and pressure distribution at the bottom surface of the valve core;

in the figure: 1. a sleeve; 2. sealing and filling; 3. a valve core main body; 4. a valve seat; 5. a spring; 6. a movable block; 7. an annular seal; 8. a piston-type valve core.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

Referring to fig. 1 and 2, a segmented piston valve core is provided in a preferred embodiment of the present invention, and is used for being mounted between a valve seat 4 and a sleeve 1 to form a valve core assembly. The main structure of the segmented piston valve core comprises a valve core main body 3, a movable block 6 and an annular sealing member 7.

Wherein the general outline shape of the outside of the spool body 3 substantially conforms to that of a conventional spool, and in this embodiment, is a hollow cylindrical shape, the bottom surface being a flat surface for serving as a sealing surface, and the peripheral surface being a cylindrical surface for fitting with the sleeve 1. The valve body 3 of the present invention differs from the conventional valve mainly in that the bottom surface thereof is not integral but is divided into pieces. The bottom surface of the valve core main body 3 is circular, and a circular through hole is formed in the center. The movable block 6 is also in a circular plate shape, the whole body is horizontally arranged in the through hole, the diameter of the through hole is larger than that of the movable block 6, the through hole and the movable block are concentrically arranged, and a circular gap is formed between the through hole and the movable block. The bottom surface of the movable block 6 is also a plane. The valve core sealing surface of the invention is formed by the bottom surface of the movable block 6 and the bottom surface of the valve core main body 3 together, wherein the bottom surface of the valve core main body 3 is kept fixed, and the movable block 6 needs to rotate to counteract the unbalanced moment born by the movable block.

Therefore, in order to achieve the above function, the valve body 3 and the movable block 6 need to be movably engaged with each other by an annular seal 7, so that the freedom of relative movement can be achieved while maintaining the seal. The annular sealing piece 7 surrounds the periphery of the movable block 6 and can fill a circular gap formed between the through hole in the bottom surface of the valve core main body 3 and the movable block 6, so that the movable block 6 is kept in airtight connection with the side wall of the through hole through the annular sealing piece 7, and the bottom surfaces of the annular sealing piece 7, the through hole and the movable block form a watertight sealing surface of the valve core integrally. At the same time, the annular seal 7 should have a telescopic elasticity, so that the movable block 6 can be turned over when subjected to an unbalanced moment. According to the stress analysis of the structure, if the movable block 6 overturns, the annular sealing element 7 is subjected to a radial stretching force and a non-radial (upward or downward) torsional bending moment at the same time, so that the expansion elasticity of the annular sealing element 7 ensures that the annular sealing element can be radially stretched and can be bent in a non-radial direction, and the normal realization of the overturning function of the movable block 6 is ensured.

The annular seal 7 of the present invention may be in various forms, such as an annular elastic film or other elastic filling material, which can form a seal between the valve body 3 and the movable block 6. Because its flexibility and elasticity, can provide the deformation space when the movable block 6 receives unbalanced moment, and then guarantee that the movable block 6 can take place to overturn.

In the present invention, a preferred embodiment is provided, in which a ring-shaped bellows structure is used as the ring seal 7. Referring to fig. 1 and 2, the annular bellows is composed of a plurality of annular bellows segments. In the traditional corrugated pipe, the radii of annular corrugated sections of the traditional corrugated pipe are the same and are sequentially spliced along the axial direction of the pipeline, so that the whole corrugated pipe has axial telescopic freedom. However, the annular corrugated pipe of the present invention is different from the conventional corrugated pipe in that the diameters of the annular corrugated sections are increased from inside to outside, they are coaxially nested and radially connected to each other, and the connection position between two adjacent corrugated sections is kept closed. Then the innermost annular corrugated joint is connected with the movable block 6, and the outermost annular corrugated joint is connected with the valve core main body 3. In the annular bellows, the degree of freedom of expansion and contraction is not axial, but in the radial direction. Meanwhile, in order to meet the deformation requirement of the non-radial bending of the annular sealing member 7 during the turning process of the movable block 6, the annular corrugated pipe should have a bending degree of freedom in the non-radial direction upward or downward along the surface of the movable block 6 through the selection of flexible deformable materials or structural optimization design.

The annular corrugated pipe can be made of materials with certain flexibility or elasticity such as plastics and high polymer materials, and the connecting positions of the annular corrugated pipe and the through holes of the movable block 6 and the valve core main body 3 can be sealed and fixed in a mode of glue adhesion, clamping fixation and the like. In a preferred embodiment, the annular corrugated pipe can be a metal corrugated pipe, and corrugated sections made of metal meet the functions of expansion and bending through a structural clamping design. The metal corrugated pipe is a spring-like structure which can stretch under the action of external force, and no gap exists between two adjacent rings. Therefore, the metal corrugated pipe, the movable block 6 and the through hole of the valve core main body 3 can be fixed in a welding mode, and the reliability of the connection node of the metal corrugated pipe and the movable block is guaranteed.

Shown in fig. 1 is a piston core assembly comprising a sleeve 1, a packing 2, a valve seat 3, a spring 5 and a segmented piston core of the present invention. Wherein, one end of the spring 5 is supported on the top surface of the movable block 6, and the other end is supported on the external valve cover and keeps a compressed state. The spring 5 is used for applying pre-pressure to the segmented piston valve core, so that the sealing surface of the segmented piston valve core is pressed on the valve seat 3 to form a sealing pair for controlling the opening and closing of the flow path, and the movable block 6 is positioned at the center of the flow path opening of the valve seat 3. The sleeve 1 is assembled outside a valve core main body 3 of the segmented piston valve core, and the sleeve and the valve core main body form a moving pair for controlling the valve core main body 3 to slide along the axial direction; the valve body 3 and the sleeve 1 are kept sealed by the packing 2.

In addition, the piston type valve core assembly can be further matched with a valve body and a valve cover assembled on the valve body to form a piston type valve. The piston type valve core assembly is arranged in a flow channel inside the valve body so as to control the on-off of the flow channel. Such a valve may be used as a pilot valve to control the internal fluid of the external system to flow to the outside.

As shown in fig. 3(a), in a general piston type valve core structure, when the piston type valve core 8 is opened, fluid flows out through a gap between the piston type valve core 8 and the valve seat 4, and the fluid is unevenly distributed, so that the fluid generates different pressures on different parts of the bottom surface of the piston type valve core 8, and finally the piston type valve core 8 is subjected to an unbalanced moment, and a turning tendency as shown in fig. 3(a) is generated. In order to facilitate understanding of the inventive concept and the working principle of the present invention, the applicant introduces a torque distribution at the bottom of the valve element in an unfragmented piston valve.

Analysis of fluid distribution and moments in piston shut-off valves by numerical simulation with inlet flow passage bend radius R_fThe diameter D of the special pipe and the height H of the valve core are distributed and set as follows: r_f100mm, 120mm and 20 mm. The calculation model selects a standard k-turbulence model. The boundary conditions are set as a pressure inlet and a pressure outlet, and the rest surfaces are slip surfaces. The inlet pressure was set to 0.25MPa and the outlet pressure to 0.1 MPa.

Fig. 4 shows the distribution of flow velocity and flow line on the bottom surface of the valve core. The position of the "low velocity zone" at the bottom surface of the spool is visually seen in the figure. After the fluid impacts the valve core in the area with the speed less than 1m/s, the fluid flows out from all directions, and the flow speed is increased continuously. As can be seen from the flow rate and pressure profiles of fig. 4, the unbalanced force profile at the bottom of the spool is primarily concentrated in the center area of the spool, which has a radial dimension of about 1/2 for a unitary spool. Under unbalanced moments, the valve core tends to tip over, and therefore in practical valve constructions, this tendency can cause the valve core to squeeze the surrounding sealing elements, thereby affecting valve performance.

In the valve core structure, the original integral valve core is divided into blocks to improve the phenomenon that the valve core is laterally turned to extrude the sealing device, and the principle is that the surface of the piston type valve core, which is in contact with the sealing device, and the surface which is subjected to unbalanced moment are divided into two parts, so that the extrusion between the valve core and the sealing device caused by the unbalanced moment is avoided. In the block type piston type valve core structure, when the valve core structure is opened, fluid flows out through a gap between the valve core main body 3 and the valve seat 4, the fluid is unevenly distributed to cause different pressures generated by the fluid to different parts of the bottom surface of the movable block 6, so that the movable block 6 is overturned as shown in fig. 3(b), the pressure applied to the bottom surface of the valve core main body 3 is uniform, the valve core main body 3 keeps the original vertical position under the action of the fluid, and the extrusion between the peripheral surface of the valve core main body and the sleeve 1 and the sealing filler 2 is avoided.

In the piston valve, the method for overcoming the unbalanced moment is as follows:

the invention divides the valve core into a valve core main body 3 which is directly contacted with the sleeve 1 and the sealing filler 2 and a movable block 6 which is used for bearing unbalanced moment by dividing the valve core into blocks. Therefore, after the valve is opened, if unbalanced moment exists in the sealing surface at the bottom of the valve core, the unbalanced moment of the sealing surface is mainly concentrated at the position of the movable block 6 in the middle of the sealing surface according to the analysis of the space position of the unbalanced moment. Under the effect of unbalanced moment, the movable block 6 overturns to offset the unbalanced moment, and the valve core main body 3 contacted with the sleeve 1 and the sealing filler 2 still can keep the original vertical direction, so that the sleeve 1 and the sealing filler 2 are prevented from being extruded due to the unbalanced moment.

The above-described embodiments are merely preferred embodiments of the present invention, which should not be construed as limiting the invention. Various changes and modifications may be made by one of ordinary skill in the pertinent art without departing from the spirit and scope of the present invention. Therefore, the technical scheme obtained by adopting the mode of equivalent replacement or equivalent transformation is within the protection scope of the invention.

Claims

1. A sectional type piston valve core is characterized by comprising a valve core main body (3), a movable block (6) and an annular sealing element (7); the bottom surface of the valve core main body (3) is a plane with a through hole in the center; the movable block (6) is horizontally arranged in the through hole, and the bottom surface of the movable block is a plane; the peripheral side of the movable block (6) is in sealed connection with the side wall of the through hole through the annular sealing piece (7) to form a water-tight sealing surface of the valve core; the annular sealing element (7) has telescopic elasticity, so that the movable block (6) can turn over when receiving unbalanced moment.

2. The segmented piston valve cartridge according to claim 1, wherein the through hole is circular, the movable block (6) is circular plate-shaped, and the diameter of the through hole is larger than that of the movable block (6), and the through hole and the movable block are concentrically arranged.

3. A segmented piston valve core structure according to claim 2, wherein the annular sealing member (7) is an annular corrugated pipe which is formed by coaxially nesting and sealing a plurality of annular corrugated sections with diameters increasing from inside to outside, the innermost annular corrugated section is connected with the movable block (6), and the outermost annular corrugated section is connected with the valve core main body (3); the annular corrugated pipe has a telescopic freedom degree in a radial direction and a bending freedom degree in a non-radial direction.

4. The segmented piston poppet of claim 3, wherein the annular bellows is a metal bellows.

5. A segmented piston valve core according to claim 4, characterised in that the metal bellows is welded to the movable block (6) and the through hole.

6. A segmented piston valve core according to claim 1, characterized in that the valve core body (3) is hollow cylindrical, the bottom surface is a circular ring plane and the peripheral surface is a cylindrical surface.

7. A piston type valve core assembly is characterized by comprising a sleeve (1), a sealing filler (2), a valve seat (3), a spring (5) and a segmented piston valve core according to any one of claims 1 to 6; the spring (5) is used for applying pre-pressure to the segmented piston valve core to enable the sealing surface of the segmented piston valve core to be pressed on the valve seat (3) to form a sealing pair for controlling the opening and closing of the flow path; the sleeve (1) is assembled outside a valve core main body (3) of the segmented piston valve core, and the sleeve and the valve core main body form a moving pair for controlling the valve core main body (3) to slide along the axial direction; the valve core main body (3) and the sleeve (1) are kept sealed through the sealing filler (2).

8. The piston-type spool assembly according to claim 7, characterized in that the spring (5) is supported at one end against the top surface of the movable block (6) and at the other end against an external valve cover and is kept in a compressed state.

9. A piston valve comprising a valve body and a bonnet mounted on the valve body, wherein the valve body has mounted therein a piston valve core assembly according to claim 7 or 8.

10. A method for overcoming unbalanced moment in a piston valve according to claim 9, characterized in that the piston valve core is divided into a valve core main body (3) in direct contact with the sleeve (1) and the packing (2) and a movable block (6) for bearing the unbalanced moment by blocks, after the valve is opened, the unbalanced moment is concentrated at the position of the movable block (6) in the middle of the sealing surface, under the action of the unbalanced moment, the movable block (6) is overturned to counteract the unbalanced moment, and the valve core main body (3) in contact with the sleeve (1) and the packing (2) maintains the original vertical orientation, thereby avoiding the sleeve (1) and the packing (2) being squeezed due to the unbalanced moment.